This invention relates to tracheal tube devices of the kind for insertion into the trachea, the device comprising a main tube encompassed towards its distal end by an inflatable bag and, extending to the interior of the bag, an inflation line by which the bag can be inflated. Generally, the inflatable bag is a cuff or a balloon.
A common feature of tracheal tube devices of this kind, such as endotracheal or tracheostomy tubes, is that bodily secretions, mucous, or other unwanted fluids can collect in the cusp between the inner surface of the body conduit and the ovate upstream surface of the inflated cuff or balloon. These bodily secretions often pass progressively between the inner surface of the trachea and the outer surface of the cuff or balloon--even though these surfaces are supposed to be in mutually sealing contact. These bodily secretions can pass from the trachea and enter the bronchi, potentially to cause lung infections. This passage of unwanted fluids past the inflated bag of the tracheal tube device is thought to be due to the patient's breathing cycle producing fluctuating inhalation/exhalation pressures on the downstream ovate surface of the inflated bag and causing the latter and/or the tracheal conduit to act somewhat in the manner of a peristaltic pump.
One proposed solution to this problem is to provide the tube device, not only with an inflation line to the distal bag but also with a suction line opening to a region above the bag. In practice however, due to the finite axial length accommodated by the tape or other fastening means required to attach the bag sealingly to the main tube of the structure, the opening from the suction line is disposed too far above the upstream ovate surface of the bag to ensure removal by suction of all the unwanted fluids collecting in that region. Even where the collar of the bag is everted, in the manner described in GB-2250440, suction may not ensure complete removal of all secretions.
It is thus clearly desirable to provide an improved tracheal tube device.